You know what? This question gets asked so often, I'm going to do something completely crazy and pointless here. Just to keep myself entertained.
Break out your ol' trusty TI-84s! Because I'M DOING THE MATH!
Okay, so the "halfway" point of this story was in Chapter 597, in Volume 61. That was when the timeskip started. So, if we decide to take that literally, that means One Piece should end somewhere around Volume 122. I doubt it will be that exact, but we have to start somewhere. So, lets assume that Oda is aiming for Volume 122 to be the final volume in this story. Giving us two, roughly equal, halves to this story.
So, how many chapters are included in each volume? Volume 111 had 12 chapters. Volume 110 had 11. Volume 109 had 10. Volume 108 had 12. Volume 107 had 12. Volume 106 had 11. Volume 105 had 10. Volume 104 had 9. Volume 103 had 11. Volume 102 had 10. So, it fluctuates a little bit, volume to volume. But if you take the mean average, you get 10.8. Let's round that up to a average of 11 chapters per volume.
Volume 111 is the latest volume to come out, stopping at chapter 1133. Let's assume each subsequent volume has a average of 11 chapters included. So, if we end on Volume 122, That means we have 11 Volumes worth of story left, and 121 chapters (107 from where we are currently). Meaning the story should end around Chapter 1254.
So, when will that come out? Well, that really depends on how many chapters get released per year. In 2024, chapters 1103-1134 were released, giving us 31 chapters that year. In 2023, 1071-1102, which is 31 chapters. In 2022, 1036-1070, which is 34 chapters. In 2021, 1000-1035, which is 35 chapters In 2020, 967-999, which is 32 chapters. In 2019, 929-966, which is 37 chapters. This time, lets be a bit more conservative. Oda does seem to be slowing down. He's only getting older and other responsibilities are starting to catch up with him. Let's assume going forth that Oda will only be able to put out 31 chapters a year, like he has for the last two years.
If we assume 31 chapters per year, that means the following: By the end of 2025, we should reach Chapter 1165. By the end of 2026 we should reach Chapter 1096. By the end of 2027, we should reach Chapter 1227. And by the end of 2028, we should reach Chapter 1258. But, since I'm predicting we're going up to 1254, that means One Piece will end 4 chapters before the end of the year.
Here is a 2028 future calendar:
https://www.timeanddate.com/calendar/?year=2028&country=1
So, here's my prediction:
One Piece ends with Chapter 1254, which will most likely release officially on November 13, 2028 (Monday). We'll likely get scans around the Friday beforehand, on November 10.
There. It is FORETOLD!
There is a lot of assumptions surrounding this. Like Oda not slowing down more than he already has. We could end up getting fewer chapters per year, if Oda's health continues to deteriorate. And the biggest assumption is that he wants the two "halves" of this story to be roughly equal in terms of volume count. But, this is my best guess, using the information we have. So, about 3 more years. That's more than my previous estimate of this ending in 2027. But, still within reason...hopefully.
This could go down as the biggest folly ever predicted on this board. But, time will tell.
As for how this would work in terms of the actual story?
I know a lot of people want Elbaph to be a long arc. But, I, personally, just don't see it being overly long. There's still that whole "don't linger on Elbaph" thing that Oda set up, after all. So...how about a compromise? The Yamato cover story seems to be wrapping up pretty soon. So, what if the next cover story after Yamato's journey through Wano is actually...Elbaph? What if the Strawhats leave Elbaph, but we continue to see the Final War play out in the cover story? Basically as the final cover story that lasts until the end of the manga?
Because, I do believe that the Final War will happen before we get to Laugh Tale. Gunko's basically already outright stated that kidnapping the kids is basically the opening salvos of the Final War. So, what if we only get glimpses of the Final War via the cover pages. And the Strawhats continue on their journey in order to actually save the World. The Final War would basically be one big distraction to allow the Strawhats to find the One Piece and stop the flooding. I feel like that would actually be rather interesting. Giving us glimpses and hype moments for the Final War, which is all we really need if the Strawhats won't be a part of it, and it mostly focuses on other factions fighting over Elbaph, like the Revolutionaries and the Gorosei and the Marines. We'd only get the highlights of the Final War, but that's all we really need to keep up the hype and anticipation.
Loki will most likely stay on Elbaph during the Final War. I feel like Loki is fulfilling the same role in this story as Shirahoshi staying on Fishman Island, and Momo and Yamato staying on Wano. Luffy is most likely going to do something on Laugh Tale that will change the entire World. All these other past friends are staying on these islands in order to help knock down the dominoes as necessary at the correct times. Shirahoshi will lead her people to the surface, the walls of Wano will get knocked down, and Loki will burn down Yggdrasil. But, it all has to happen at the correct time, most likely AFTER Luffy does something on Laugh Tale, in order for this big centuries-long plan to work.
I think the God's Knights are going to get called away to help Shamrock do something on Mariejois. He's probably going to need backup to deal with something over there (possibly Dragon and the Revolutionaires making their move). The God's Knights will have to leave their game halfway through. And the Strawhats will have basically only have won by forfeit.
Then, they'll meet up with Scopper and he'll most likely tell them some secret about how to defeat the Regeneration abilities. I could see there being a VERY short training arc, but perhaps not. I'm envisioning something like this: "Normally, learning this techniques requires a person to train for...2 years!" "2 years! No way, old man! We can all learn this technique in...3 days!" Giving us a inversion of
3D2Y. That's right! I'm predicting we may get a
2Y3D!
After that, we're on our way! Probably to Lodestar? We might meet the Man Marked By Flames to grab that final Road Poneglyph on the way. But, after that it's probably Laugh Tale. Then....we may go to the Underworld to visit the Ancient Mining Operation hinted at by the 1138 Mural. And if that's the way it goes, chances are that'll be the end of the manga. We may or may not visit the Moon, but probably only briefly, if at all.
I honestly don't think we have that much longer to this story. I've said it before, but Oda's body just cannot survive another decade of doing this. It's slowly killing him. I feel bad for asking for another 2 or 3 years. I think this is...reasonable. Not ideal, but reasonable. And I'll admit, I AM extending things out from what I've predicted before. But, I think it really depends on how bad Oda's health ends up getting. I could see things getting abbreviated, if Oda's health takes a major turn for the worse.